Adjustment means for loud speakers



Aug@ El@ R92@ LSQQ N. HEYMAN ADJUSTMENT MEANS FOR LOUD SPEAKERS Filed Oct. 20, 1924 Patented Aug.. lill), i926.'

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NFCHOLAS HEYMAN, OF BUFFALO, YORK, ASSGNOR T0 FEDERAL TELEIIEI-IONE MANUFACTURING CORPORATION, OF BUFFALO, NEW YORK, .A CORPORATION OF .NEW YORK.

ADJUSTMENT Manns non noun srnairnns.

rlhisinvention relates r"to adjustment means-tortelephone receivers and particularly tortlieloud speaker type of receiver commonly used in connection with radio I're ceiving systems.

I rllheA adjustment system lto which this in vention is especially directed provides a control, manually operatedby, the user,'ove r the amount of the force exerted bythe magnet system o t the receiver en the vibrating iifieniber,(suchl as armature or diaphragm,

acted on by the "magnet, this `control `being j preferably so arranged as toA varyf the air gap between magnet poles and vibrating `member-. .j

, Vlit has been recognized heretotorethat such a control left to the discretionand skill of .the user, over receivers of the, loud speaker type, isdesi-rable invorder to obtain best results in volume and quality of sound, and in general to ensure the greatest eihciency possible iinder' the varying conditions of radio reception.

ltis found, however, that difficulties arisev in connection IWith the provision of 'such control means, for example, freezing or block-4 ing of. the diaphragm by too vclose or too Wide adjustment, inaccessibilityof the adjustinent means, misalignment and looseness 'Lio sign, easily understood and operated by the. user, certain inaction, and adapted to ac v curate and at the same timelovv cost -nianu-` in thereceiver parta-lack of permanency of the adjustment, mechanical Weakness and complexity and short life of the adjustmentsystem, too great `delicacy ofadjustmentjfor satisfactory operation by the user, too great iiianufacturing'cost involved in the precision required to ensure accurate and permanently .practical Working of the adjustment system. f

' The object of the present invention is to i overcome these and other lo'litlicu'lties which vhave been met with, y and to provideva,re ceiver for loud speaker and like use having a control system of simple 'and rugged. de-

acture.

ln accordance with the invention a supporting member in the form of a casing is provided in which are mounted the magnet element, andthe diaphragm element or the moving element whichv actuates a dia# phragm. In the preferred form of the inventioyi a diaphragm is secured to the cas- Vingin any suitable manner, and a lmagnet member issecured .to a base member rotatable and slidable With respect to the casing.

" The 'magnet' base comprises a'portion or portions so tted vto-tlie casing as to maintain the .magnet member and the diaphragm inclose alignment at alltimes. actuating means in the form of bearing members and.

bearing faces and comprising for example pins engaging in slots, or other coacting elements, and associated with the casing and With the magnet base, arprovided. 'These actuating means are so' formed that a partial rotation of the magnetbase With reference vention, and for further objects andl afd-v vantages thereof which Will hereinafter appear.

Figure l is a sectional view of one embodiment of theiiivention. v'

, Figure 2 is a'perspective View of a-cylindricul member having bearingfaees `formed therein` and -Which in the embodiment sho/Wn iii Fig. l is secured to themagnet base melnf ber.

Figure '3 is` a plan viewof a s pring'which in the embodimentiof Fig. l vis interposed between the casing Wall andra control'member which is fastened to the magnet bas'e.

The same referencecharacter refers to the samepart wherever it occurs in the 'dravvings. A

In Fig. l, Which is a vertical'section on :the centerline of a preferred form 'of the,

cover screws 3.1 magnet base member 5 isy mounted on casing 1 and is a close rotating and sliding fit thereon.

'In addition,` a resilient Imeans such as a spring is associated with the in any es i etl

. an has ln the present embodiment ot the invention, magnet base member 5 is 'formed ot two pieces. @ne of these pieces is acup shaped member 6 and the other is a cyliii:

drical member Y. rlhese pieces are firmly fastened together as by rivets, one of which, El, is shown in Fig. l. A magnet 9 is mounted within the base member 5 and kclamped under pole pieces l0.v Extensions ot the pole pieces serve as a pair of coil cores .ll for coils 12. Base member 5 is secured to a rotatable control member in the form of a cap .13 which is preferably of insulating material. Fastening means which ivi secure cap i3 and also magnet 9 to base member 5 comprise screws 14 passing through pole pieces l0 and cup shaped member 6, and into a spacer block l5 which may be secured to the cap in any suitable manner as by moulding into the cap. preferable fastening means o' cap to block which permits the removal ot1 the cap with-` out disturbing the magnet assembly 4comprises screws, one oi' which, 16, 1s shown in lig. l, which ass through the cap and are screwed into tie block. AConnecting wires l? are connected in any suitable manner to the coils and are'led out preferably at the center of cap i8.

'llie actuating means associated with the magnet base and the casing and by which the length oit the airgap is controlled comprise, inthe present embodiment 'ot the -invention,. a bearing .tace "formed in the piece 7, and bearing 'members proyecting' from the casing and into engagement with the bearing face. er single continuous beariiig face may be 'formed as by toi-ming a single` slot extending wholly -orpartially around the said piece i7. But as shown in the perspective view ot Fig. 2, it is preterable tor construction reasons to Jform the bearing :tace in two or more sections, as i8,

` which-may be the sides ot openings, such as slots i9, formed in piece 7., llhese slots 19, the sides of which iii the preferred form ot the invention thus term bearing tace sections as 18, are cut in approximate spiral Jrorm in the surface ot the cylindrical piece.

rlhe bearing members which engage withY spring tending to lorce the magnet base eithell lward the casing, Adepending on the arrangearther away from or `farther in tonieiit adopted. l.

'he preferred itorm oi the invention illustrated here" i the spring as 22 neeaeee may be ot tlat compression type, shown in plan in Fig. 3, and with a plurality oit' corrugations 23. rElie spring is so placed as to bear against the edge 2d of casing l and against the inner face 25 of cap 9, andimder compression tends to move the magnet poles, which are rigidlyV connected tothe cap, farther away from the diaphragm, which is secured to the casing,

lt will be seen by reference to Fig. l that the entire assembly of magnet base 5, magnet and coil structures carried thereon and attached control member, cap i3, is held within the casing by the screws 20 Which are iiiied to the'casing wall and project iiito the slots formed iii the wall ot the magnet base.. The slots and pins are so 'shaped that a desired degree ot rotation ot the slotted piece 7 and'parts attached thereto is provided. ris the slots are formed .spirally in the surface oi the ring piece,

the pin and slot action results in moving the magnet base farther into or -tarther out Yfrom the casing asthe cap is rotated, with a resulting change in the length ot the gap between pole pieces and diaphragm. 2;. comparatively minute and gradual change in the length ot the air gap is thus accomplished by a comparatively large movement et the easily accessible and easily manipulated control member formed by the large diameter-cap piece i3. f

lt will further be seen that very exact parallelism ot magnet poles and diaphragm is maintained under all conditions oit adjustment by reason of the extended bearing sur tace between the casing, which carries the diaphragm, and the wall sui-tace ot the magnet base member, which carries. the magnet poles.

'"lhe spring 22 is preferably arranged to exert considerable pressure between casing and cap so as to hold pins 2l firmly against bearing faces 18 of the slots. rjhe spring,

"therefore, acts automatically to taire up clearances in the working parts and'to maintain exact anygiven setting ot the air gap. Further, the spring preferably exerts siiicient pressure between the casing and `the asseiiiblyof magnet base and cap to hold the lcap at any givenv point in its partial iota tion with reference, to the casing. Other securing means may, however, be provided,v as set screw 2G in the` wall ot the casing and bearing against the wall of the magnet base. The amount ot adjustment of the air gap provided may vary within wide limits. rl suiiicient range 'for ordinary purposes may be .0 15 or .0*16. In the tivo pin and v70 slot arrangement oi" the adjustment coi. means as herein illustrated; the pins and rotation slots are so placed as to provide a ot the cap with reference to y:he ca i500 or i600, The initial setting of strument such that with the cap I: O l

to its limit to narrowv the air gap, the pole pieces and diaphragm are still. safely out of contact. lit will ,be understood from the drawings' that at thisl setting of the adjustnientmeans, which brings vthe air gap to a predetermined minimum, .the pins 21 ,will

strike the ends ottheir corresponding slots.

Further rotation of the cap which would result'in bringing the pole` shoes and diaphrag'i'n i't'contact is thus prevented by'.v this stop means comprised in theadjustmeiit means. 'llhe adjustment range ot the' air gap,'therefore, covered by a 150o or 160"y .rotation of the -cap is from a predetermined narrow gap,x which may 'be'.008l with poles and diaphragm safely out 'of Contact at any pull or' the magnet, to a predetermined maximum gap wider4 than the minimum by .015

or .016. .With this ,arrangement oiE thev 2 control meansthe change in length of air gap as the cap is rotatedis about '.00'1' for a' 10 movement of the cap. l

' lit is to be noted thatthe construction de- I scribed, with a'spiralof small lead :formed in the piece?-7 gives the equivalent of a comparatively line. thread screw, and *the accurate-.and delicate adjustment of such a screw, but withoutthe costand ditlicultyof con# struction met withn the production. of screws of large diameter and line thread.

The cylindrical piece .7 may be a complete ring',lor oit the split ring form shown in Fig. 2; `lin this latter 'typeet 'construction the ,forming ofgbearin'g faces, as 'by the punching of slots 19, may be done in the flat' and the piece afterward bent 'to proper shape.l In,- stead of the two ieee 'construction of base member 5 it is evidentthat the piece 7 may\` be dispensed with'entirely andbearing faces formed in Wall portionsA of the member G directly. lt is,v preferable, however, to use the two piece construction, as shown, in

which, for' example, the .piece 7- may be cheaply madefol" steel flat or tube stock, well suited to act as `a bearing material, and the member t of aluminum yor# other non-mag netic material. Further, as alternative forms of the' invention, the ring piece may be securedrigidly to the'casing andthe pins or otherbbea-ring members may be fixed te the wall portion of member 6, `or bearing faces may be formed, as by slotting, directly in the casing wall' and the piece 7 dispensed with. As a further-alternate form within the scope of the invention, the spring means may be so arranged as to tend to move the magnet base and'attached parts farther into the casing, instead of out from the casing, yand the coacting bearing faces and bearingI members may then be located and formed either essentially as already explained, or

may be located elsewhere'oii the casing mem* ber, and on the structure, comprisingthe magnetbase, which moves relatively thereto.

These and other changes in. constructional features from the precise form of the invention illustrated anddescribed, may be made Without departing from the scope of the in-y vention as set vforth inthe appended claims.

What is claimed'is: Y l. lin a telephone receiver, a cylindrical casing, a vibrating elementjmounted onthe casing, a magnet-member comprising a pole `piece in proximityl to the Vibrating element,

a base member `for `the magnet membencomprising a Wall portion closely adjacent said casing, and means comprising a bearing face elementl isi maintained/as the" gap between-- them. is varied. Y,

2. In a'- telephone receiver, a cylindrical Casing, a Vibrating element mounted lon the casing, Ya magnet member comprising a pole piece in proximity to the vibrating. element, a base member for the magnet member comprising a wall portion closely adjacent. said casing, means'comprising abearing face and a bearing member coacting therewith for varying the gap between pole piece and vibrating element, said means further-comprisingaV control member secured tossaid magnet base and accessible .trom outside said' casing, said bearing face being formed `spirally in said wall portion and said4 bear.

ing member being secured to said casing,

whereby rotation of said control member-. Aand the magnet base secured thereto with respectto the casing varies the gap between pole piece and vibrating element, said wall portion lhaving a smooth bearing surface lwhich is a close rotatingand sliding tit on a smooth bearing 'surface ofsaid casing and said Wall portion providing a comparatively large bearing `for saidmagnet base member bn said casing, whereby exact alignment of pole piece and vibrating element -is maintained as the gap between them is varied. y

3. In a telephone` receiver, a cylindrical casing member, a diaphragm mounted on the casing, a magnet member comprising a pole piece in proximity to the' diaphragm, a base for' the magnet, said base comprising a wall member litt-ed closely to the casing member, and means associated with the wall member and the casing member comprising abearing facev of lspiral form in one of said members and a bearing'member securedto the other of said members coacting with said bearing.

A the gap between pole piece 'and diaphragm,

Ulf

`said wall member havinga smooth bearing surface which is a close rotating and sliding lit on a smooth bearing surface ot' said casing and said wall member providing a com paratively large bearing ior said magnet base member on said casing, whereby exact aiigmnentotl pole piece and diaphragm iS maintained as the gap between them is varied.

ln a telephone receiver, a cylindrical casing, a diaphragm mounted on the cas-ing, a magnet, member tfol'nprising a pole piece in proximity to the diaphragima base nrembcr tor the magnet member, the base member having a wall portion litted closely to the casing, and means comprising a bearing face formed spirally in said Vall portion and comprising a bearing member coaeting with the bearing face and secured to said casing whereby rotation ot the base member with respectto the casing varies the gap between pole piece and dia phragnn'said wall portion having a smooth bearing surface which is a close rotating` and sliding lit on a smooth bearing surface oit said casing and said wall portion providing` a compara ively large bearing for 'said magnet ybase member on said easing, whereby exactalignment ot pole piece and diaphragm is maintained the gap between them is varied.

in a telephone receiver, a cylindrical casing member, a vibrating element mounted on the casing member, a magnet comprising` a pole piece in proximity tothe vibrating element, a base for the magnet, said base comprising a wall member fitted closely 'to said :asing member and rotatable and axially slidable thereon,- means associated with the wall member and the cas-ing member :For varying the gap between pele-piece andvibrating eiement said means comprising a bearing tace of spirai form in one o'i said members and a bearing member in the other oi' said members coacting with said bearing tace, and resilient means associated with the easing member ,and with the magnet base member for maintaining` said bearing member in Contactwith said bearing face, said wall member and said casing member having` smooth coaeting bearing surfaces and said wall member providing a comparatively large bearing` surface tor said magnet base on said casing` member, wh eieby exact aiignment ont pole piece and vibrating element is maintained as the gap between pcie piece and vibrating element is varied.

G. in a telephone receiver, casing, a diapi'iragm mounted on the casing, a magnet member comprising a pole piece in proximity to *the diaphragm, a base member for the magnet member, the base member having a wall portion fitted closely to thecasing, and

means comprising a bearing member secured to the casing and engaging a wall ot a slot roi-med 1n the wall portion of the base mem- .ber whereby rotation of the base member ity' to the diaphragm, base member :for

the magnet member, the base member having a. wall portion tted ciosely to the casing, means comprising a bearing member .secured to the casing and engaging a wall oi a slot formed in thewall portion ot the base member whereby rotation of the vbase member with respectl to the casing varies the gap between pole piece Iand diaphragm, and resilient means associated with the casing and with the magnet base whereby said bearine member is maintained in Contact with a wail of said slot.

8.' in a telephone receiver, a casing, a diaphragm mounted on the casing, a magnet member comprising a pole piece in proximity to the diaphragm, a base member for the magnet member,l the base member having a wall portion itted closely to the casing, means comprising a bearing member secured to the casing, andA engaging a wall ot a slot formed in the wall portion of the base member whereby rotation of the base member with respect to the casing varies the gap between pole, piece and diaphragm, a control member secured to the magnet base member, and a resilient means interposed between the casing and the controi member whereby said bearing member is maintained in Contact with a wall of said slot.

E). in a telephone receiver, a cylindrical casing member, a vibrating element mounted on the `casing, a magnet member comprisinga pole-piece in proximity to the vibrating element, a base for the magnet, said base comprising a wall member fitted closely to the casing member, and means associated with the wail member and the casing member comprising a bearing 'tace ot spiral torni in one of said members and a` bearing mem` ber secured to the other of said members vcoacting with said bearing tace, whereby rotation of the base member with respect 'to the casing member varies the gap between pole piece and vibrating element, said wall member having a smooth bearing surface which is a ciose rotating and siiding tit on a smooth bearing surface of said casing and wail member providing a comparatively large bearing for said magnet base member on said casing, whereby exact alignment of pole piece and vibrating eiement is maintained` asv the gap between them is varied. witness whereof, have hereunto signed my name.

NECHLS Sii 

